Interview With Richard Restak, author of 'Think Smart.'

In the last decade, improved imaging technologies have given scientists a new window on the brain, and Restak has turned the latest research into a practical guide for brain health. In Think Smart: A Neuroscientist’s Prescription for Improving Your Brain’s Performance, the neurologist, neuropsychiatrist and professor of clinical neurology at George Washington University Medical Center explains that, like any body part, the brain needs regular workouts to keep in shape.

The brain’s enemies aren’t added years, Restak says. Rather, distraction, sloth, stress, boredom, even obesity and loneliness are the bugaboos that can dial down mental productivity. Depression, in fact, can actually shrink the hippocampus—part of the brain that plays a major role in memory and spatial navigation. [Read an excerpt from the book.]

We need to care for that three-pound organ above the eyes, Restak says. After all, it has a hundred billion cells with a million billion connections between them instructing us on everything from brushing our teeth to recalling names to running a marathon to writing a novel. Restak spoke with AARP Bulletin Today about his prescriptions for boosting intelligence, memory and fending off age-related decline.

Q. What have been the biggest surprises about the brain in the last decade?

A. We’ve learned how plastic the brain is, how much it can change. As we’re talking right now, sharing new information, our brains are changing, creating new connections between neurons. We used to think you were born with a certain capacity for intelligence, but now we know you can continually enhance it. You can better your mental acuity, your speed of processing information and your memory.

Q: We often think of older, more mature brains as losing faculties, but does a brain that’s been around longer have advantages?

A: Another surprise. We all start out with a large number of cells, of neurons, and over time many are lost. Yet as we mature, the brain can actually work better. It compensates for losses by increasing the networking capacity of the neurons you have left, so you have fewer but stronger connections. I can’t think of anything else that runs better after it loses parts. The brain is really unique in this way.

Q. How much power, then, do we really have over how well our brains work?

A. Quite a bit. First, we have control over the basic elements of intelligence. Attention is the bedrock of intelligence. The more we learn to focus in a world of distraction, the smarter we get and the better our brains function. Memory then follows naturally from attention. Clearly, if you don’t attend to something, you can’t remember it. Attention also allows you to improve performance in other brain functions. Sensory memory, long-term and short-term memory, fine motor skills, observational skills, the ability to reason—if you work them, they will improve.

Q. Does working to improve memory help other brain functions?

A. One kind of physical exercise—say, swimming—may bring about improvements in general health, such as blood pressure, respiration and metabolism. But mental exercises need to be more focused. If you spend time working your memory, it won’t do much for your power of logic or hand-eye coordination. You have to focus on each component separately.